Die cleaning systems and related methods

ABSTRACT

Implementations of methods of forming a plurality of semiconductor die may include forming a damage layer beneath a surface of a die street in a semiconductor substrate, singulating the semiconductor substrate along the die street into a plurality of semiconductor die, and removing one or more particulates in the die street after singulating through applying sonic energy to the plurality of semiconductor die.

BACKGROUND 1. Technical Field

Aspects of this document relate generally to systems and methods forsingulating die from semiconductor substrates.

2. Background

Semiconductor devices are typically formed on and into the surface of asemiconductor substrate. As the semiconductor substrate is typicallymuch larger than the devices, the devices are singulated one fromanother into various semiconductor die. Sawing the semiconductorsubstrate is a method used to separate the semiconductor die from eachother.

SUMMARY

Implementations of methods of forming a plurality of semiconductor diemay include forming a damage layer beneath a surface of a die street ina semiconductor substrate, singulating the semiconductor substrate alongthe die street into a plurality of semiconductor die, and removing oneor more particulates in the die street after singulating throughapplying sonic energy to the plurality of semiconductor die.

Implementations of methods of forming a plurality of semiconductor diemay include one, all, or any of the following:

The semiconductor substrate may be silicon carbide.

Forming a damage layer may further include irradiating the die streetwith a laser beam at a focal point within the semiconductor substrate atone or more spaced apart locations beneath the surface of the die streetto form the damage layer.

Forming a damage layer may further include irradiating the die streetwith a laser beam at a focal point at a first depth within thesemiconductor substrate at one or more spaced apart locations beneaththe surface of the die street and irradiating the die street with alaser beam at a focal point at a second depth within the semiconductorsubstrate at one or more spaced apart locations beneath the surface ofthe die street.

Singulating the semiconductor substrate may include sawing thesemiconductor substrate.

The method may include ablating a portion of the material of the diestreet using a laser.

The semiconductor substrate may be singulated using stealth dicing.

Applying sonic energy may include applying sonic energy between 20 kHzto 3 GHz.

Implementations of methods of forming a plurality of semiconductor diemay include irradiating a semiconductor substrate with a laser beam at afocal point below a die street to form a damage layer, sawing thesemiconductor substrate along the die street into a plurality ofsemiconductor die, and removing one or more particulates in the diestreet after singulating through applying sonic energy to the pluralityof semiconductor die.

Implementations of methods of forming a plurality of semiconductor diemay include one, all, or any of the following:

Applying sonic energy may include applying sonic energy between 20 kHzto 3 GHz.

The semiconductor substrate may be silicon carbide.

The method may include ablating a portion of the material of the diestreet using a laser.

Forming a damage layer may further include irradiating the die streetwith a laser beam at a focal point at a first depth within thesemiconductor substrate at one or more spaced apart locations beneaththe surface of the die street and irradiating the die street with alaser beam at a focal point at a second depth within the semiconductorsubstrate at one or more spaced apart locations beneath the surface ofthe die street.

The method may include spraying the plurality of semiconductor die witha liquid while applying the sonic energy.

The method may include applying sonic energy to the saw blade whilecutting the semiconductor substrate.

Implementations of methods of forming a plurality of semiconductor diemay include singulating a silicon carbide semiconductor substrate alonga die street into a plurality of semiconductor die, applying sonicenergy to the silicon carbide semiconductor substrate, and removing oneor more particulates in the die street after singulating the siliconcarbide semiconductor substrate through applying sonic energy to theplurality of semiconductor die.

Implementations of methods of forming a plurality of semiconductor diemay include one, all, or any of the following:

Applying sonic energy may include applying sonic energy between 20 kHzto 3 GHz.

Applying sonic energy to the silicon carbide semiconductor substrate mayinclude directly applying sonic energy to a spindle coupled with a chuckcoupled to the silicon carbide semiconductor substrate.

The method may include either spraying the plurality of semiconductordie with a liquid while applying the sonic energy or immersing theplurality of semiconductor die in a liquid while applying the sonicenergy.

The semiconductor substrate may be singulated using stealth dicing.

The foregoing and other aspects, features, and advantages will beapparent to those artisans of ordinary skill in the art from theDESCRIPTION and DRAWINGS, and from the CLAIMS.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations will hereinafter be described in conjunction with theappended drawings, where like designations denote like elements, and:

FIG. 1 is a cross-sectional side view of an implementation of a damageddie street in a semiconductor substrate;

FIG. 2 is a cross-sectional side view of a second implementation of adamaged die street in a semiconductor substrate;

FIG. 3 is a cross-sectional side view of a saw cutting through the diestreet of FIG. 2;

FIG. 4 is a cross-sectional side view of a semiconductor substrate afterhaving been cut through;

FIG. 5 is a cross-sectional side view of a semiconductor substratesubmersed in a liquid with sonic energy applied to the liquid;

FIG. 6 is cross-sectional side view of a third implementation of adamaged die street in a semiconductor substrate;

FIG. 7 is a cross-sectional side view of a saw cutting through the diestreet of FIG. 6;

FIG. 8 is a cross-sectional side view of a semiconductor substrate afterhaving been cut through; and

FIG. 9 is a cross-sectional side view of a semiconductor substratesubjected to sonic energy while being sprayed with a liquid.

DESCRIPTION

This disclosure, its aspects and implementations, are not limited to thespecific components, assembly procedures or method elements disclosedherein. Many additional components, assembly procedures and/or methodelements known in the art consistent with the intended semiconductor diewill become apparent for use with particular implementations from thisdisclosure. Accordingly, for example, although particularimplementations are disclosed, such implementations and implementingcomponents may comprise any shape, size, style, type, model, version,measurement, concentration, material, quantity, method element, step,and/or the like as is known in the art for such semiconductor die, andimplementing components and methods, consistent with the intendedoperation and methods.

A wide variety of semiconductor substrate types exist and are used inthe process of manufacturing various semiconductor devices. Non-limitingexamples of semiconductor substrates that may be processed using theprinciples disclosed in this document include single crystal silicon,silicon dioxide, glass, silicon-on-insulator, gallium arsenide,sapphire, ruby, silicon carbide, polycrystalline or amorphous forms ofany of the foregoing, and any other substrate type useful forconstructing semiconductor devices. Particular implementations disclosedherein may utilize silicon carbide semiconductor substrates (siliconcarbide substrates) of any polytype. In this document the term “wafer”is also used along with “substrate” as a wafer is a common type ofsubstrate, but not as an exclusive term that is used to refer to allsemiconductor substrate types. The various semiconductor substrate typesdisclosed in this document may be, by non-limiting example, round,rounded, square, rectangular, or any other closed shape in variousimplementations.

Referring to FIG. 1, a cross-sectional side view of an implementation ofa damaged die street 4 in a semiconductor substrate 2 is illustrated. Asillustrated, the street 4 is the area of the semiconductor substrate 2between die 6 and 8 and extends across the thickness of thesemiconductor substrate 2. Since this is a cross sectional view, justtwo die 6, 8 are visible in this view, but the street extends across aplurality of die spaced apart across the surface of the semiconductorsubstrate 2. In various implementations, the semiconductor substrate 2may include a device layer 12. The device layer may include a pluralityof power semiconductor devices, such as, by non-limiting example, aMOSFET, an IGBT, a thyristor, any other power semiconductor device, andany combination thereof. In other implementations, one or more of theplurality of semiconductor devices may include a non-power semiconductordevice.

In various implementations, the method of forming a plurality ofsemiconductor die may include forming a damage layer 14 beneath asurface 16 of the die street 4 in the semiconductor substrate 2. Thedamage layer may be formed from either the front side 18 or the backside20 of the semiconductor substrate 2. In various implementations, theforming the damage layer 14 may include forming a plurality ofperforations 22, or holes, within the damage layer 14. In otherimplementations, no holes are formed in the saw street but a portion ofthe material in the saw street may still be damaged or altered to aweaker condition. In various implementations, the damage layer may beformed through a laser, etching, heating of the material of the street,cooling of the material of the street, implanting the material of thestreet, or any other method useful for disrupting the crystallinestructure of the die street. In implementations where a laser is used,the laser beam may irradiate the material of the street 4 at a focalpoint beneath a surface 16 of the street 4. Because the laser beamcauses localized heating at the focal point, the crystalline structureof the material at the focal point becomes disrupted. In otherimplementations, the method may include ablating the material, damagingthe material, or ablating and damaging the material using a laser. Thelaser may include parameters the same as or similar to any parameters ofany laser disclosed herein.

As illustrated by FIG. 1, the damage layer 14 may not extend all the waythrough the saw street 4, but may be concentrated near the surfacecorresponding with the source of the damage. Thus, as illustrated byFIG. 1, assuming the damage layer was formed via a laser, the laserirradiated the semiconductor substrate 2 through the device layer 12. Inother implementations, the damage may be formed from the backside 20 ofthe semiconductor substrate 2. While the damage in FIG. 1 is illustratedas being at discrete points or holes, in various implementations, thedamage may be distributed continuously or semi-continuously through thematerial of the die street. In other implementations, the damage layermay extend through the entire depth of the saw street 4. In variousimplementations, and as illustrated by FIG. 1, the damage layer 4 may beformed across the width of the saw street 4 and may be continuous orsemi-continuous. However, in other implementations, such as theimplementation illustrated by FIG. 2, the damage layer may be formedonly near the sidewalls of the semiconductor die.

Referring to FIG. 2, a cross-sectional side view of a secondimplementation of a damaged die street in a semiconductor substrate 24is illustrated where the damage 26 is only near the sidewalls of the diestreet 28. The damage 26 may extend substantially entirely through adepth of the die street 28, as illustrated by FIG. 2, while in otherimplementations the damage 26 may be located closer to a front side 30or a backside 32 of the semiconductor substrate 24. In still otherimplementations, the method of forming a plurality of semiconductor diemay not include forming a damage layer in the die street, rather, thesemiconductor substrate may be singulated without forming any kind ofdamage in the die street.

In various implementations, the method may include forming a scribe markin a top surface of the die street with a stylus. Depending on thepressure, speed, and/or tip characteristics of the stylus, the scribemark may result in removal of material from the street and/or theformation of a crack that propagates down into the material of thestreet from the scribe mark following the crystal structure of thesemiconductor substrate. The stylus may be both used in implementationsof die streets of semiconductor substrates already having a damage layeras well as implementations where the stylus is used to create the damagelayer within the die street.

Referring to FIG. 3, a cross-sectional side view of a saw cuttingthrough the die street of FIG. 2 is illustrated. The method of forming aplurality of semiconductor die may include coupling the backside 32 to achuck 34 or platform used to support the semiconductor substrate 24. Themethod may also include singulating the semiconductor substrate 24 alongthe die street 28 into a plurality of semiconductor die 36. In variousimplementations, and as illustrated by FIG. 3, a saw blade 38 may beused to singulate the semiconductor substrate 24. As illustrated, thesawing of the substrate takes place once the substrate has been mountedon cutting tape and oriented device side up from the orientation in FIG.2. As illustrated, in various implementations the saw blade 38 is madeof a composite material that includes a binding matrix 42 that holdsparticles of diamond grit 40 therein. During the sawing process, thematerial of the matrix 42 wears away exposing the diamond grit 40particles, which also eventually fall out of their place in the bladeafter being used in the sawing process for a time. In this way, freshdiamond particles are constantly being exposed and available for useduring the entire lifetime of the blade. The damage layers weaken thecrystal structure of the semiconductor substrate, and so allow the bladeto remove the material in the street more easily. Since the material iseasier to remove, then less wear on the blade occurs and the bladelifetime can be increased. Also, in some implementations, the sawprocess may be able to take place more quickly since the material can beremoved more quickly. Since the saw blade 38 is a consumable as it wearsover time and requires changing, increasing the blade lifetime and/orincreasing the number of substrates which can be cut using the saw bladecan reduce the processing cost per substrate. In other implementations,other saw blades made of different materials may be used. Such sawblades may or may not include the diamond grit 40.

During the sawing process, particularly for hard substrates such assilicon carbide, the saw blade can glaze or otherwise prevent thematerial of the matrix from properly abrading (due to accumulation ofmaterial from the cutting tape and/or material from the substrate beingsawn), causing the blade to no longer be bringing new diamond gritparticles to the surface of the blade. This reduces the effectiveness ofthe blade when cutting, decreasing cutting speed and/or causingincreased sidewall damage to the die, which can reduce die strength,particularly for thinned die. In various implementations, a sonic energyassisted sawing system may be utilized. In such implementations, a sonicenergy source may be coupled with a spindle that is rotatably coupledwith saw blade. During operation, the sonic energy from the sonic energysource is transmitted down the spindle as vibrational energy causing thesaw blade to correspondingly vibrate during operation. As a result, thematrix vibrates against the material of the substrate being cut andabrades more easily, allowing fresh pieces of diamond grit to be morereadily exposed. Also, in various implementations, the sawn slurrymaterial of the substrate itself can act as grit against the blade dueto the vibration action and also assist in the cutting process of unsawnsubstrate material as well. The observed effect of sonic energy enhancedsawing is that the sawing process proceeds more quickly, blade lifetimesare longer, and/or the sidewall damage observed following the sawingprocess is reduced. Also, for substrates where the Mohs hardness of thematerial being sawn is close to the hardness of the diamond grit (likesilicon carbide), the benefits of using sonic enhanced singulation maybe particularly advantageous, due to the generally slow sawing processand high blade wear rates observed for such materials. The effect of theincreased efficiency of the cutting process where sonic energy isapplied to the spindle can be observed in lower spindle currents beingrequired during the sawing process. The parameters of the sonic energyapplied may be the same as or similar to any parameters of any sonicenergy disclosed herein.

In other implementations, the method of forming a plurality ofsemiconductor die may include singulating the semiconductor die throughother methods or processes aside from cutting or sawing thesemiconductor substrate. In implementations where a score mark is formedin the die street using a stylus, the semiconductor substrate can bestretched or flexed through mounting the substrate onto cutting tape ordie attach film and stretching the film. In this way, the cracks formedby the scribe mark then complete propagating through the thickness ofthe substrate thus singulating the plurality of die which can then bepicked from the tape. The ability for the scribe mark to create a crackcapable of permitting direct scribe and break separation using a processlike this depends on the crystallographic orientation of the crystalplanes of the particular semiconductor substrate being used (and whetherthe substrate is a single crystal substrate or not). In some substrates,since the crack will follow the path of least resistance, the crack mayactually attempt to propagate at some angle from the scribe mark intothe die. In such implementations, the scribe mark may simply be used asa material removal/additional street damage technique to aid in furtherdamaging the material in the street and/or removing material beforesawing using a saw blade using any of the techniques disclosed in thisdocument. The use of the scribing technique may improve die strength asit may reduce the amount of material sawn or eliminate the need for saw,depending on the crystallography of the particular semiconductorsubstrate. Such implementations may also be combined with the varioussawing implementations disclosed herein.

The method of forming a plurality of semiconductor die may includesingulating the semiconductor die through stealth dicing. As usedherein, stealth dicing may include forming a damaged or modified layerwithin the die street of a semiconductor substrate. The damaged layermay be formed using any method disclosed herein. After the damaged layeris formed, stealth dicing may include coupling the semiconductorsubstrate to a tape expander. The semiconductor substrate may then beexpanded resulting in singulation of the semiconductor substrate alongthe damaged die street into a plurality of die. Stealth dicing mayincrease the number of die formed from the semiconductor substrate asthe die street may be narrower than that which a saw blade can producedue to saw blade width, saw kerf width, and other factors controllingthe ultimate width of a saw cut street.

The method of forming a plurality of semiconductor die may includesingulating the semiconductor die through etching. In variousimplementations, the semiconductor substrate may be singulated using awet etch or a dry etch. In still other implementations, the method offorming a plurality of semiconductor die may include singulating the diethrough ablating portions of the die street. In such implementations,following creating of the damage layer, a laser beam configured toablate the material of the street using, by non-limiting example, aparticular laser type, beam width, pulse energy, repetition rate, power,and any other laser parameter may be passed across the material of thestreet. Also, in some implementations, a jet of gas may be applied atthe focal point of the ablation laser beam. In some implementations,this jet of gas may be at ambient temperature and designed to blow theslag from the laser in a desired direction either out of the laser beamor relative to the street. In other implementations, the jet of gas maybe cooled relative to ambient temperature and/or a temperature of thesubstrate and may act to thermally shock the substrate at the point ator close behind the heated ablation point. In these implementations, theremaining material of the street may fracture along the crystallographicplane of least resistance and result in singulation of the die on eachside of the street from each other. Where cold gas is used, lessablation by the laser may be needed to achieve singulation of the die,which can reduce the amount of slag deposited on the die and/or increasethe ultimate die strength following singulation.

Referring to FIG. 4, a cross-sectional side view of a semiconductorsubstrate after having been singulated is illustrated. In variousimplementations, after singulating the plurality of semiconductor die36, variously sized particulates/slivers/chips 44 may be coupled to thesidewalls of the plurality of semiconductor die. The particulates 44 maybe remnants of the die street 28, tape, backmetal, or any othercontamination or material from the substrate. Such particulates 44 mayprove problematic as they may flake off after the singulation processand/or during the assembly process. In various implementations, suchparticulates may contaminate waste water (particularly those thatcontain copper). Further, if a mold compound of a semiconductor packageis coupled to the particulates 44, the particulates 44 may break offfrom the remainder of the semiconductor substrate and may compromise thestructure of the final chip.

Referring to FIG. 5, a cross-sectional side view of a semiconductorsubstrate submersed in a liquid with sonic energy applied to the liquidis illustrated. In various implementations, the method may includeimmersing the plurality of semiconductor die 36 in a liquid 46. Theliquid 46 may include, by non-limiting example, water, a surfactant, amixture of water and surfactant, and/or any other solvent and/or solute.As illustrated by FIG. 5, the tape 34 may also be immersed in theliquid. In various implementations, the plurality of semiconductor die36 on the tape 34 may be held or supported in the bath or othercontainer in which they are submerged using a chuck (which may be avacuum chuck in various implementations).

In various implementations, after the plurality of semiconductor die 36are immersed in the liquid 46, the method of forming a plurality ofsemiconductor die may include removing one or more particulates 44 inthe die street 28 after singulating the semiconductor substrate throughapplying sonic energy to the plurality of semiconductor die 36. Invarious implementations, the sonic energy is applied directly to theliquid 46 through a sonic energy source 48 and is applied to theplurality of semiconductor die 36 through the liquid 46. A wide varietyof frequencies may be employed by the source of sonic energy 48 whichmay range from about 20 kHz to about 3 GHz. Where the sonic frequenciesutilized by the ultrasonic energy source 48 are above 360 kHz, theenergy source may also be referred to as a megasonic energy source. Inparticular implementations, the sonic energy source 48 may generateultrasonic vibrations at a frequency of 40 kHz at a power of 80 W. Invarious implementations, the sonic energy source 48 may apply afrequency of between about 30 kHz to about 50 kHz or about 35 kHz toabout 45 kHz. However, in various implementations, other frequencieshigher or and/or lower than 50 kHz may be employed, including megasonicfrequencies. A wide variety of power levels may also be employed invarious implementations.

The sonic energy source 48 may employ a wide variety oftransducer/oscillator designs to generate and transfer the sonic energyto the spindle in various implementations, including, by non-limitingexample, magnetostrictive transducers and piezoelectric transducers. Inthe case where a magnetostrictive transducer/oscillator is utilized, thetransducer utilizes a coiled wire to form an alternating magnetic fieldinducing mechanical vibrations at a desired frequency in a material thatexhibits magnetostrictive properties, such as, by non-limiting example,nickel, cobalt, terbium, dysprosium, iron, silicon, bismuth, aluminum,oxygen, any alloy thereof, and any combination thereof. The mechanicalvibrations are then transferred to the portion of the ultrasonic energysource that contacts the liquid. Where a piezoelectrictransducer/oscillator is employed, a piezoelectric material is subjectedto application of electric charge and the resulting vibrations aretransferred to the portion of the ultrasonic energy source that contactsthe liquid. Example of piezoelectric materials that may be employed invarious implementations include, by non-limiting example, quartz,sucrose, topaz, tourmaline, lead titanate, barium titanate, leadzirconate titanate, and any other crystal or material that exhibitspiezoelectric properties.

Referring to FIG. 6, a cross-sectional side view of a thirdimplementation of a damaged die street in a semiconductor substrate isillustrated. Similar the implementation illustrated by FIG. 1, themethod of forming a plurality of semiconductor die may include forming adamage layer 50 beneath a surface 52 of the die street 54 in thesemiconductor substrate 56. As illustrated by FIG. 6, the damage layermay be formed using laser irradiation. In implementations where a laseris used, the laser beam 58 may irradiate the material of the street 54at a focal point 60 beneath the surface 52 of the street 54. Because thelaser beam 58 causes localized heating at the focal point 60, thecrystalline structure of the material at the focal point is disrupted.In other implementations, the method may include ablating the material,damaging the material, or ablating and damaging the material using alaser. As illustrated by FIG. 6, the semiconductor substrate 56 issilicon carbide.

The degree of damage at the focal point 60 is determined by manyfactors, including, by non-limiting example, the power of the laserlight, the duration of exposure of the material, the absorption of thematerial of the substrate, the crystallographic orientation of thesubstrate material relative to the direction of the laser light, theatomic structure of the substrate, and any other factor regulating theabsorbance of the light energy and/or transmission of the induced damageor heat into the substrate. The wavelength of the laser light used toirradiate the street 54 is one for which the material of the particularsemiconductor substrate is at least partially optically transmissive,whether translucent or transparent. Where the substrate is a siliconcarbide substrate, the wavelength may be 1064 nm. In variousimplementations, the laser light source may be a Nd:YAG pulsed laser ora YVO4 pulsed laser. In one implementation where a Nd:YAG laser is used,a spot size of 10 microns and an average power of 3.2 W may be usedalong with a repetition frequency of 80 kHz, pulse width of 4 ns,numerical aperture (NA) of the focusing lens of 0.45. In anotherimplementation, a Nd:YAG laser may be used with a repetition frequencyof 400 kHz, average power of 16 W, pulse width of 4 ns, spot diameter of10 microns, and NA of 0.45. In various implementations, the power of thelaser may be varied from about 2 W to about 4.5 W. In otherimplementations, however, the laser power may be less than 2 W orgreater than 4.5 W.

As illustrated, the focal point 60 of the laser light forms a locationof rapid heating and may result in full or partial melting of thematerial at the focal point 60. The point of rapid heating and theresulting stress on the hexagonal single crystal structure of the SiCsubstrate as a result of the heating/cooling results is cracking of thesubstrate material along a c-plane of the substrate. Depending on thetype of single SiC crystal used to manufacture the boule, the c-planemay be oriented at an off angle to the second surface of about 1 degreeto about 6 degrees. In various implementations, this angle is determinedat the time the boule is manufactured. In particular implementations,the off angle may be about 4 degrees.

During operation, the laser is operated in pulsed operation to createnumerous overlapping spots of pulsed light while passing across thesurface of the substrate. As a result, a continuous/semi-continuouslayer/band of modified material is formed within the wafer. In otherimplementations, the laser may be operated in continuous wave moderather than pulsed mode to create the band of modified material. Instill other implementations, the damage layer may be formed only nearthe sides of the die street 54, similar to the implementationillustrated by FIG. 2. As illustrated by FIG. 6, the stress caused bythe focal point 60 causes cracking along the c-plane in the material ofthe street 54 in one or both directions along the c-plane. These cracks62 are illustrated as spreading from the focal point 60 area (where themodified layer/band is located) angled at the off angle in FIG. 6. Invarious implementations, the cracks 62 may be located below the focalpoint 60, above the focal point 60, or spread directly from the focalpoint 60, depending on the characteristics of the laser and the methodof application of the laser to the material. In various implementations,the length of the cracks 62 into the substrate is a function of thepower of the laser applied. By non-limiting example, the depth of thefocal point was set at 500 um into the substrate; where the laser powerwas 3.2 W, the crack propagation from the modified layer/band was about250 um; where the laser power was at 2 W, the crack lengths were about100 um; where the laser power was set at 4.5 W, the crack lengths wereabout 350 um.

As illustrated in FIG. 6, the laser beam 58 is in the processing ofmaking a third pass along the street at a third spaced apart locationfrom the two previous passes. In various implementations, one, two, ormore passes may be conducted in any street. The various passes may usethe same laser parameters and feed speeds/rates or may be conductedusing different laser parameters and different feed speeds/rates. Thedisrupted material and cracks from the laser irradiation form a damagelayer beneath the surface 52 of the street 54. The damage layer breaksup the structure of the semiconductor substrate material (in the case ofSiC, the hexagonal crystalline structure of the substrate) therebyweakening the strength of the material. Other focal points 64 like focalpoint 60 are illustrated that are a different depth into the material ofthe street 54 (distance beneath the surface 52 of the street 54). Inthis way, multiple damage layers can be formed within the material ofthe street 54. Generally, the damage layer at the deepest depth into thematerial of the street would be formed first, followed by the nextdamage layer, and so forth. However, in other implementations, thereverse may be done, particularly where the focal points do not directlyoverlap each other but are staggered instead. As illustrated, theirradiation is being conducted from the back side 66 of the substrate,or the side of the substrate that is opposite the side on which thesemiconductor devices have been formed (device side 68). In otherimplementations, however, depending on the material in the street, thelaser irradiation can be performed from the device (front) side 68 ofthe substrate, similar to the implementation illustrated by FIG. 1.Where laser irradiation is conducted from the back side 66 of thesubstrate 56, the use of back side cameras to align the wafer using thedevice side of the wafer may be used to align the wafer to ensure thatthe laser irradiation is properly aligned with the streets themselvesand avoids the area of the plurality of die.

Referring to FIG. 7, a cross-sectional side view of a saw cuttingthrough the die street of FIG. 6 is illustrated. The method of forming aplurality of semiconductor die may include singulating the semiconductorsubstrate 56 into a plurality of semiconductor die 70. The semiconductorsubstrate 56 may be singulated using any method disclosed herein. Asillustrated by FIG. 7, a saw blade 72 may be used to remove the materialof the die street. The saw blade 72 may be any type of saw bladepreviously disclosed herein, including a saw blade having diamond grit,or, as illustrated, a saw blade without diamond grit.

Referring to FIG. 8, a cross-sectional side view of a semiconductorsubstrate after having been singulated using a saw blade is illustrated.Upon singulating the semiconductor substrate 56, one or moreparticulates/slivers/chips 74 may be coupled to the sidewalls of theplurality of semiconductor die. The particulates 74 may be remnants ofthe die street 28, tape, backmetal, or any other contaminant ormaterial. These particulates 74 may be removed using any methoddisclosed in this document.

Referring to FIG. 9, a cross-sectional side view of a semiconductorsubstrate subjected to sonic energy while being sprayed with a liquid isillustrated. In order to remove the particulates 74, the method offorming a plurality of semiconductor die 70 may include applying a sonicenergy to the plurality of semiconductor die 70. In variousimplementations, a source 76 of the sonic energy may directly apply theenergy to a spindle 78 coupled to the chuck 80 or platform supportingthe semiconductor substrate 56. In this manner, the sonic energy isapplied to the substrate 56 through the chuck 80. In suchimplementations, the semiconductor substrate may be either be immersedin a liquid as previously described herein, or, as illustrated by FIG.9, the method may include spraying the semiconductor substrate 56 withliquid from a sprayer 82 while the sonic energy is applied to thesemiconductor substrate. The combination of the sonic energy with thespray may remove the one or more particulates 74 from the sidewalls ofthe plurality of semiconductor die 70. The spray may be any liquid,including, by non-limiting example, water, surfactant, a combination ofwater and surfactant, and/or any other solvent and/or solute disclosedin this document.

In places where the description above refers to particularimplementations of semiconductor die and implementing components,sub-components, methods and sub-methods, it should be readily apparentthat a number of modifications may be made without departing from thespirit thereof and that these implementations, implementing components,sub-components, methods and sub-methods may be applied to othersemiconductor die.

1. A method of forming a plurality of semiconductor die, the methodcomprising: forming a damage layer beneath a surface of a die street ina semiconductor substrate; singulating the semiconductor substrate alongthe die street into a plurality of semiconductor die; and removing oneor more particulates in the die street after singulating throughapplying sonic energy to the plurality of semiconductor die.
 2. Themethod of claim 1, wherein the semiconductor substrate is siliconcarbide.
 3. The method of claim 1, wherein forming a damage layerfurther comprises irradiating the die street with a laser beam at afocal point within the semiconductor substrate at one or more spacedapart locations beneath the surface of the die street to form the damagelayer.
 4. The method of claim 1, wherein forming a damage layer furthercomprises: irradiating the die street with a laser beam at a focal pointat a first depth within the semiconductor substrate at one or morespaced apart locations beneath the surface of the die street; andirradiating the die street with a laser beam at a focal point at asecond depth within the semiconductor substrate at one or more spacedapart locations beneath the surface of the die street.
 5. The method ofclaim 1, wherein singulating the semiconductor substrate comprisessawing the semiconductor substrate.
 6. The method of claim 1, furthercomprising ablating a portion of the material of the die street using alaser.
 7. The method of claim 1, wherein the semiconductor substrate issingulated using stealth dicing.
 8. The method of claim 1, whereinapplying sonic energy further comprises applying sonic energy between 20kHz to 3 GHz.
 9. A method of forming a plurality of semiconductor die,the method comprising: irradiating a semiconductor substrate with alaser beam at a focal point below a die street to form a damage layer;sawing the semiconductor substrate along the die street into a pluralityof semiconductor die; and removing one or more particulates in the diestreet after singulating through applying sonic energy to the pluralityof semiconductor die.
 10. The method of claim 9, wherein applying sonicenergy further comprises applying sonic energy between 20 kHz to 3 GHz.11. The method of claim 9, wherein the semiconductor substrate issilicon carbide.
 12. The method of claim 9, further comprising ablatinga portion of the material of the die street using a laser.
 13. Themethod of claim 9, wherein irradiating the semiconductor substratefurther comprises: irradiating the die street with a laser beam at afocal point at a first depth within the semiconductor substrate at oneor more spaced apart locations beneath the surface of the die street;and irradiating the die street with a laser beam at a focal point at asecond depth within the semiconductor substrate at one or more spacedapart locations beneath the surface of the die street.
 14. (canceled)15. The method of claim 9, further comprising applying sonic energy tothe saw blade while cutting the semiconductor substrate.
 16. A method offorming a plurality of semiconductor die, the method comprising:singulating a silicon carbide semiconductor substrate along a die streetinto a plurality of semiconductor die; applying sonic energy to thesilicon carbide semiconductor substrate; removing one or moreparticulates in the die street after singulating the silicon carbidesemiconductor substrate through applying sonic energy to the pluralityof semiconductor die.
 17. The method of claim 16, wherein applying sonicenergy further comprises applying sonic energy between 20 kHz to 3 GHz.18. The method of claim 16, wherein applying sonic energy to the siliconcarbide semiconductor substrate further comprises directly applyingsonic energy to a spindle coupled with a chuck, the chuck coupled to thesilicon carbide semiconductor substrate.
 19. The method of claim 16,further comprising one of spraying the plurality of semiconductor diewith a liquid while applying the sonic energy and immersing theplurality of semiconductor die in a liquid while applying the sonicenergy.
 20. The method of claim 16, wherein the semiconductor substrateis singulated using stealth dicing.